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The crystal structure of mawbyite, PbFe2(AsO4)2(OH)2

Published online by Cambridge University Press:  05 July 2018

Kharisun
Affiliation:
Department of Chemistry, Flinders University, GPO Box 2100 Adelaide, South Australia 5000, Australia
M. R. Taylor
Affiliation:
Department of Chemistry, Flinders University, GPO Box 2100 Adelaide, South Australia 5000, Australia
D. J. M. Bevan
Affiliation:
Department of Chemistry, Flinders University, GPO Box 2100 Adelaide, South Australia 5000, Australia
A. D. Rae
Affiliation:
Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia
A. Pring
Affiliation:
Department of Mineralogy, South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia

Abstract

The crystal structure of mawbyite, PbFe2(AsO4)2(OH)2 has been refined. The mineral is monoclinic, C2/m with a = 9.066(4), b = 6.286(3) c = 7.564(3) Å, β = 114.857(5)°, Z = 2; the structure has been refined to a conventional R = 4.3% using 361 observed reflections [I> 3σ(I)]. The structure contains chains of edgesharing Fe(O,OH)6 octahedra which are linked by AsO4 tetrahedra and Pb atoms in distorted square antiprismatic co-ordination. The hydrogen bonding network in the structure has been modelled using bond valence calculations. Mawbyite is confirmed to be isostructural with tsumcorite and dimorphous with carminite and the relationship between these two structures is discussed.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1997

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Footnotes

*

Permanent address: Fakultas Pertanian, Universitas Djenderal Soedirman, P.O. Box 125, Purwokerto 53123, Jawa-Tengah, Indonesia.

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